Research Highlights

Kinfe Teweldebirhan, Mark Miesch, and Sarah Gibson investigate the role and impact of converging flows toward Bipolar Magnetic Regions (BMR inflows) on the Sun’s global solar dynamo. These flows are large-scale physical phenomena that have been observed and so should be included in any comprehensive solar dynamo model.

Chun-Yen Huang, Tzu-Wei Fang, Arthur Richmond, Timothy Fuller-Rowell, Jenn-Yenq Liu research expressions of newly established Rayleigh-Taylor (R-T) instability growth rates, then perform calculations using the thermospheric and ionospheric conditions based on the coupled Whole Atmosphere Model and Ionosphere Plasmasphere Electrodynamic model (WAM-IPE). The parameters used in this calculation include the field-line integrated conductivities and currents, which consider the Quasi-Dipole Coordinates and the modifications to the equations of electrodynamics.

Authors Joseph McInerney, Liying Qian, Han-Li Liu, Stanley Solomon, and Susan Nossal decided to apply the WACCM-X climate model to the upper atmosphere for the decades from the 1920s to 2010s. This type of modeling application will be useful to predict what will happen in the century ahead as greenhouse gases increase and humans make efforts to reverse the increase.

Hanli Liu, Peter Lauritzen, and Francis Vitt use the high-resolution whole atmosphere model to study small-scale wave propagation from the lower atmosphere into the thermosphere. Using this high-resolution model, which can partially resolve the small-scale waves, they can directly quantify the force exerted by these waves on the general circulation in the thermosphere.

Steven Cranmer, Rohit Chhiber, Chris Gilly, Iver Cairns, Robin Colaninno, David McComas, Nour Raouafi, Arcadi Usmanov, Sarah Gibson, Craig DeForest review the properties of Alfvén surface and discuss its importance in models of solar wind acceleration, angular momentum transport, MHD waves and turbulence, and the geometry of closed coronal loops. Simulations results and data analysis techniques are used to determine the location of the Alfvén surface.

B. Raphaldini, M. Dikpati, A. A. Norton, A. S. W. Teruya, S. W. McIntosh, C. B. Prior, and D. MacTaggart investigate how global toroid patterns and local magnetic field topology of solar active region AR12673 together can hindcast occurrence of the biggest X-flare of cycle 24. We infer that minimum-phase storms can be forecast only hours ahead, while flare-prone active regions in peak-phase can be anticipated at least a month ahead from global toroid patterns.

Matthias Rempel, Georgios Chintzoglou, Mark C. M. Cheung, Yuhong Fan, and Lucia Kleint—Solar flares are bursts of high-energy radiation that are associated with sunspots. NOVA highlights this newly published research that uses models to study what happens when sunspots collide and under what conditions these collisions cause solar flares.

Philip Judge evaluates images from the Solar Orbiter spacecraft to determine the steadiness of coronal heating. The widely-held belief that the outer atmosphere of the Sun is in a continuous state of magnetic turmoil is pitted against the EUI data with very illuminating results.

This fascinating memoir covers the scientific life of Dr. Andrew Skumanich, starting with his family’s background and their immigration to the US. It continues with Andy's childhood, early education, his influential introduction to science, and finally his illuminating career, which started at Los Alamos Scientific Laboratory in the 1950s and then continued in solar physics at the High Altitude Observatory (National Center for Atmospheric Research).